jeudi 29 janvier 2015

Animals that don't Exist

The
Eternal Goose

The
eternal goose, Anser invictus,
is a close cousin of the bar-headed goose. Breeding annually in the
high plateaus of the Himalaya, the birds spend most of the year
flying at extremely high altitudes. Several eye-witnesses have
reported sightings of the geese from commercial airliners from all
over the world.

Scientists
have been interested in the eternal goose for a long time, especially
the mechanisms that allow it to fly at heights of up to 10'000 meters
(~33'000 feet), and the selective pressures that have pushed them to
choose this lifestyle. In recent years, the geese have been tracked
year round, and the data obtained showed that the animals were even
more amazing than thought at first.

If
before it was believed that 10'000 meters was their maximum altitude,
it has now been shown that it is in fact their cruising
altitude. Indeed, after their short reproductive period, the animals
will fly off, quickly reaching their cruising altitude, at which they
will remain until it is time to breed again.

Analysis
of flight routes, as well as wind patterns, show that the geese, once
they reach their desired height, barely have to make any effort at
all. The wind currents will simply let them glide along, until, nine
months later, they once again arrive at their breeding grounds. While
the birds are at high altitude, they reduce their metabolism to a
minimum, consuming almost no energy at all. The cold of the upper
reaches of the atmosphere, combined with a special protein that
prevents ice-crystals from forming, helps prevent cellular damage.
And of course, the high altitude makes sure that they are safe from
most, if not all, predators.

Due
to the fact that they spend most of their time in a form of suspended
hibernation, eternal geese are among the most long-lived animals on
the planet. How long exactly they can live has not yet been
determined, because since the studies begun, over sixty years ago,
most of the animals that survived their first year have stayed alive.

Today,
however, the geese face a growing threat from climate change. The
changes in temperatures provoked by global warming affect the air
currents, and leave the geese either caught up in the gales, and
unable to descend at their destination, or stranded in unfamiliar
lands at irregular intervals. Wether this will cause the extinction
of the species, or allow them to colonize new habitats, remains to be
seen.